magento-test/app/code/Magento/MediaContentSynchronizationCatalog/etc/di.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="Magento\MediaContentSynchronizationCatalog\Model\Synchronizer\Category">
        <arguments>
            <argument name="fields" xsi:type="array">
                <item name="image" xsi:type="string">image</item>
                <item name="description" xsi:type="string">description</item>
            </argument>
        </arguments>
    </type>
    <type name="Magento\MediaContentSynchronizationApi\Model\GetEntitiesInterface">
        <arguments>
            <argument name="entities" xsi:type="array">
                <item name="catalog_product" xsi:type="string">Magento\Catalog\Api\Data\ProductInterface</item>
                <item name="catalog_category" xsi:type="string">Magento\Catalog\Api\Data\CategoryInterface</item>
            </argument>
        </arguments>
    </type>
    <type name="Magento\MediaContentSynchronizationCatalog\Model\Synchronizer\Product">
        <arguments>
            <argument name="fields" xsi:type="array">
                <item name="description" xsi:type="string">description</item>
                <item name="short_description" xsi:type="string">short_description</item>
            </argument>
        </arguments>
    </type>
    <type name="Magento\MediaContentSynchronizationApi\Model\SynchronizerPool">
        <arguments>
            <argument name="synchronizers" xsi:type="array">
                <item name="media_content_category_synchronizer" xsi:type="object">Magento\MediaContentSynchronizationCatalog\Model\Synchronizer\Category</item>
                <item name="media_content_product_synchronizer" xsi:type="object">Magento\MediaContentSynchronizationCatalog\Model\Synchronizer\Product</item>
            </argument>
        </arguments>
    </type>
    <type name="Magento\MediaContentSynchronizationApi\Model\SynchronizeIdentitiesPool">
        <arguments>
            <argument name="synchronizers" xsi:type="array">
                <item name="media_content_catalog"
                      xsi:type="object">Magento\MediaContentSynchronizationCatalog\Model\Synchronizer\SynchronizeIdentities
                </item>
            </argument>
        </arguments>
    </type>
</config>